Plowlike scraper for cleaning interior surfaces of water mains and other pipes



Aprll 18, 1950 L. R. ROBINSON ETAL 2,504,730

PLOW-LIKE SCRAPER FOR CLEANING INTERIOR SURFACES OF WATER MAINS AND OTHER PIPES Filed Dec. 20, 1946 2 Sheets-Sheet 1 3nventors 2c www- W Bu I F W I M (Ittornegs.

L. R. ROBINSON ET AL 2,504,730 PLOW-LIKE SCRAPER FOR CLEANING INTERIOR SURFACES OF WATER MAINS AND OTHER PIPES 2 Sheets-Sheet 2 April 18, 1950 Flled Dec 20, 1946 an/Z 0 71/ v ar/424m Wdttomegs,

Patented Apr. 18, 1950 PLOWLIKE SCRAPER FOR CLEANING INTE- I RIOR SURFACES OF WATER MAINS AND OTHER PIPES Lawrence R. Robinson, Mount Lebanon, Kyle I. Robinson, Glenshaw, Earl 0. Berger, Bellevue, and Walter S. Lang, Pittsburgh, Pa., assignors to Pittsburgh Pipe Cleaner Company, Pittsburgh, Pa., a corporation of Pennsylvania Application'D ecemb'er 20, 1'946,'Serial No. 717,544

13 claims;

This invention relates to pipe cleaning tools or plow-like scrapers for cleaning the inner surfaces of water mains and other pipes, more particularly those with uneven inner surfaces.

The practice of cleaning hard deposits from the inner surfaces of pipe conduits by moving scrapers through the pipes is well known. A common form of cleaning apparatus is described in Haydock Patents 1,531,439 and 1,593,072. Such apparatus includes a flexible hollow stem or spring steel coil about .the circumference of which are mounted a number of rearwardly diverging leaf springs carrying plow-like scrapers on their outer ends. Mounted on the hollow stem behind the plows are one or more cup-like pistons of flexible material. Water pressure behind the pistons forces them and the scraper plowsthrough the pipe. The plows will cut through the deposits in the pipe and scrape it quite clean, unless there are pits or other de pressions in the pipe surface which the plows can not enter. If rivet heads are inside the pipe the plows may slide over some of them without cleaning between them. When a pipe is being cleaned preparatory to being coated'inside with a protective coating, it is quite important that all surfaces and depressions be scraped clean if possible. Some cleaning tools are provided with separate spring fingers to' aid the plows, but such fingers are rather stiff and increase the length of the tools or form separate tools which must follow the plows. It also has been found that the spring fingers often are bent back so'far by the projections in the pipe that the fingers break. Further, the fingers which ride along and scrape the bottom of the pipe and those which contact the outside bend of the pipe as the cleaner is moved around such a bend are subjected to a great deal of pressure which flattens the fingers and causes breakage.

"It is an object of this invention'to provide a pipe cleaning tool on which are mounted resilient scraping members adapted to clean in and around irregularities of the pipes inner surface. Another object is to provide such a tool in which the resilient scraping membersare protected from breakage.

' According to the invention, the plow has a base from which project a pair of forwardly converging sidewalls whose outer edges are adapted to cut through the layer of foreign matter inside the pipe as the plow is moved through the pipe. A plurality of spring fingers are carried by the plow between its side walls. When unrestrained, these-fingers will project outwardly beyond the side wall cutting edges, and therefore they will spring into any pipe depressions that the cuting edges of the plow can not enter. On the other hand. the plows side walls limit the amount that projections in the pipe can bend the fingers, whereby breakage of the fingers is substantially avoided.

The invention is illustrated in the accompanying drawings, of which Fig. 1 is a fragmentary longitudinal section through a pipe showing two scraper plows engaging its inner surfaces; Figs. 2 and 3 are side and plan views, respectively, of one embodiment of the invention; Figs. 4 and 5 are plan and side views, respectively, of another embodiment; Figs. 6 and '7 are plan and end views, respectively, of a further modification of the invention; and Fig. 8 is a side view of the third embodiment with the rear portions of the plows side wall cut away.

Referring to Figs. 1, 2 and 3 of the drawings, the plow has a triangular base I with side walls 2 substantially perpendicular to the base and converging toward its apex. The outer edges of the side walls preferably are serrated or provided with saw teeth 3 for cutting through and loosening deposits on the inner surface of a pipe. However, for the purposes of this invention, such edges can be smooth in which case they will cut more as a knife than as a saw. Attached to the apex or front end of the plow by means of a metal plate 4 is an inclined metal loop ii.

When plows like this are used in cleaning apparatus, such as the Haydock tool referred to above, leaf springs 6 (Fig. 1) diverging rearwardly from the central supporting hollow stem (not shown) extend through. the loops 5 and.

have their outer ends secured to the plow bases. While the-tool isbeing movedthrough a pipe to clean it, springs 6 are bowed backwardly by the plows which the pipe- Wall holds substantially parallel. to the pipe axis. .Thus, the leaf springs press the plows outwardly with considerable force. I

It is a feature of this invention that this plow will clean out depressions in the pipe wall not reached by teeth 3. For this purpose a plurality of spring fingers 8 are mounted on base -I be-. tween side walls 2, and these fingers will project beyond the teeth if not restrained. The front ends of the fingers are secured by rivets 9 or other suitable meansto the plow base from.

which they curve rearwardly and outwardly so as normally to-extend beyond teeth 3 in a di-' rection substantially: perpendicular to the base, as shown in Fig. 2 .Preferably, as shown in Fig.

' thecsr i nsffl 2196M I theplows are" #9 :sm

.3, the fingers are arranged in rows extending across the base withthe fingers in each rowstaggered relative to those in the adjacent rows.

'The' l a p fg a ti fi igilfifiafi 1 1 trated in; il eil a'v e s plowsiare hawn in tandem, although usually the second plow will follow between two plows ahead of it. The plows-V cut through the deposit (notshown for the sake of elearness) to the innerjsui iageqq f#8929226 along which the teeth scrape. The-outer-ends of the spring'fingers likewise scrape along the pipe Surface by which theysaaemressedeaewasaly between the side walls of stheeplow. Whenathe plow reaches a depressionasuchteeth will pass over the pit -=w-1th9 TM However, one or more of the spring fingers;

3,5 wa e-pith} t cleani spring into the pit and scrape forei g; natter from it. Similarly, as a plow passes ov era projection, such as a rivetai I, the plow willbe tilted} brepushedawayffrom'ithe pipe wall -momentarily:

bye-the ri'vet,1 withsthe resultathat certainsaxeas (if-'ZthBLDiPQ-"ma'Y not'be scraped by' the plowiteethb ='Ehe aspi ing Fiingers, ehowever, ewillbrea'ch: those areas-.r-and' clean waroundethe' rivet.

' '-:=An:-ad-vantage of m'ounting thespring fingers the plow is that the distance theyean iberbent baek toward the f- 'plow base that is; the-amount theycan-be straightened is ?limited )by "the pldwl's side walls which space ;its base from the-pipe i s urged outwardly y the nrwmxres $1. 93 Mallgirectly behind the pin. The fingers extend straightaw ay f rorn the plate and then are curved ly ro s s he pin and back between the d .7 which they then curve outy and f0 ardly. After making such a loop -eD!":Qi;;;abQi1ltihe2Pii the free ends of the fingers utwardlyabeyond the outer edge of the s a-suflicient distance to function k ni aer as the spring fingers of the embo mentspreviously described. An advantgg gopi gg theijpgers about the pinsin the 'directignfshowh is that when their outer'ends are-pressed rearwardl v and inwardly, the coils about the pinsare enlarged or'loose'ned instead 'of beingitighteneckwvhichunightfizvreal z"the fingers V I at the -coils; "i 'llheisideiwalls'r2&voitthe plow pre- -'3E'-hisprecludes breakage of thezfingers-whichahas V been aproblem where th fingerswwer-eQindepend ently mounted andcould be ovenstressedrinapassin'g-over projectionsg -E ven -incases whereitzmay bl thanlarger ones-and which will accommodate {themselves to the pipeand -scrape i13 clean.

In the modification shown -.:in Figsk 4 and 5the fingersifi, howeyer,--=iinstead of being separate curyed spr-ings attached d-iiectW -to the -'-plow 7 base, are integralwith the rear end of-aseparate triapgulal plateg'l 9i boltedorrriireted to the base by me inane-mannamr ilel "ng 'of'these fingers is -avoi de d hy' the side w is bin "#159 th -ere u t a emalt 99 when or tolitbeimentien: tra ed imFi aece mmp ie v wl artioularly useful when 1 mm be necessary -to protect thesprin'g fingers frorn -breakage, thereare advantages'eimmounting a rela-tivel y large numbehofi fingersclose $0-f V gather =in-a small space on-asupporting base-.-or plate attached to'the outer-end of-a lea= spring.

-It; zrer'n liils-theuse offingers that are ano'ee' fiext mw has a forwardly tapered-base i 5 and cen- 7 verging side wallsflii with-i serratedcutting edges H} like the-plow describedabove. 'Thespring r breakagelot thezfin'gers'iseavoidedp 1practicedaby:othenafoizmsethamithosea specifically zillusttatedaandsdflseribed.

weiclaimz' w r V A=.plaweadapted'totbermovedfithroughearpipe "having-@amuneven innensurface tor-scrape ieeeign matter from irthata surface,-: said? plowacornprising a 'base a pain of'foewandly ;converging'ssideewalls substant-iallyperpendicuiar $0$aidl=ba8e and 'haming outer edges-. adaptedato -eutisthrough ssaid" mountedwbetweemsaid sidewallsahd urgedsou-te I :wardly beyond said eutting edges tcleamforeign matter tram tpipe;i;dep1zes'sionsanot xeaehed'gby 7 said edges fsaidsideeiwalls limiting" thei distanee said -flngerseanwbeibentitoward zthe-rbaseewhereby having-amuneyenZinnensurfaeeatQscrapeiforeign and base. of th n sn fi rine cu e s h s-type T are adva ta e usl u e? wh n-cl a n Pa cuelrl ner t a a s i iereis subs ance Lfm a V having an'1nneveminner surface' ease-rape foreign forwardlytapered baseaiazpair ofi ferwai dl c can if verging side wallssubstantiallyperpendiculaieto' g;outen-edgestaidapted t cut n'thi f esmm e More d J ta fwe s ed gs -"throughawhieh 5T cut througheeaid foreigngn iatterg d -oi pusvedeepeingii gers mounte sbetwee side-swalls with their-outennd$- urgedwutwardly I gmatter iromisthat suriace,esaid plow comprising .a forwardly tapered ba se, a pairaof firwardly -converging-side walls substantiallwperpendicular to saidbaseranwhavingaoutereedgese adantedato laaplur 'heyond-asaidacutting-edgesmo elean -foreignmatte trem pipetdepressionsanotreachedebysaidedges, :ji said fingerswein'gdisposed m' agger-edrelation,

-'-:3.:Aplow-adapted to beemo'ved thzxough matter trom*thatsurface; said andicuwed -rearwasdly and outwar outerendssurgedoutwardly beyond: a dedges toc lean"forggn a natterirenvpipe depres r siens;'-'not-geaehedeb edgessaid id wai lief acne patent men aspi'pe aid toward the base, whereby breakage of the is avoided.

4. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantially perpendicular to said base and having outer edges adapted to cut through said foreign matter, a plate attached to said base between said side walls, and spring fingers integral with said plate and having cutting ends urged outwardly beyond said cutting edges to clean foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance said fingers can be bent toward the plate by pipe projections encountered by the fingers, whereby breakage of the fingers fingers is avoided.

5. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantiall perpendicular to said base and having outer edges adapted to cut through said foreign matter, and a metal plate attached to said base between said side walls, the rear end portion of the plate being divided lengthwise into a plurality of spring fingers that are bent outwardly to provide cutting ends urged outwardly beyond said cutting edges for cleaning foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance said fingers can be bent toward the plate by pipe projections encountered by the fingers, whereby breakage of the fingers is avoided.

6. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantially perpendicular to said base and having outer edges adapted to cut through said foreign matter, and a metal plate attached to said base between said side walls, the rear end portion of the plate being divided lengthwise into a plurality of strips that are twisted and bent outwardly to provide cutting ends urged outwardly beyond said cutting edges to clean foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance said cutting ends can be forced toward the plate by pipe projections encountered by said ends, whereby breakage of the strips is avoided.

7. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantially perpendicular to said base and having outer edges adapted to cut through said foreign matter, spaced retaining members extending across said base between said side walls, and a plurality of spring fingers wound about each of said retaining members with the outer ends of the fingers urged outwardly beyond said cutting edges to clean foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance the outer ends of said fingers can be bent toward the base by pipe projections encountered by the fingers, whereby breakage of the fingers is avoided.

8. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantially perpendicular to said base and having outer edges-adapted to cut through said foreign matter, a plate secured'to said base between said side walls, spaced, retaining members extending across said plate, means connecting said members to the plate in spaced relation thereto, and a plurality of spring rods coiled around each retaining member, the inner ends of the rods being connected to said plate, and the outer ends of the rods being urged outwardly beyond said cutting edges to clean foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance said outer ends of the rods can be pressed toward theplate by pipe projections encountered by the rods, whereby breakage of the rods is avoided.

9'. A plow adapted to be moved through a pipe having an uneven inner surface to scrape foreign matter from that surface, said plow comprising a forwardly tapered base, a pair of forwardly converging side walls substantially perpendicular to said base and having outer edges adapted to cut through said foreign matter, a plate secured to said base between said side walls, spaced retaining members extending across said plate, means connecting said members to the plate in spaced relation thereto, said plate being provided with a plurality of holes adjacent said members, and a plurality of spring rods having their inner ends mounted in said holes, said rods being coiled around said retaining members with the outer ends of the rods urged outwardly beyond said cuttin edges to clean foreign matter from pipe depressions not reached by said edges, said side walls limiting the distance said outer ends of the rods can be bent toward the plate by pipe projections encountered by the rods, whereby breakage of the rods is avoided.

10. In a pipe cleaning tool adapted to be moved through a pine to scrape foreign matter from the inner surface thereof and having a plurality of rearwardly diverging leaf springs, a base member supported by the outer end of each of said leaf springs, a pair of forwardly converging side walls substantially perpendicular to said base and havin outer edges adapted to cut through said foreign matter, and a plurality of spring teeth mounted on each of said base members and curved rearwardly and outwardly with their outer ends urged outwardly beyond said cutting edges to scrape foreign matter from the pipe, said side walls limiting the distance said fingers can be bent toward the base.

11. In a pipe cleaning tool ada ted to be moved through a pine to scrape foreign matter from the inner surface thereof and having a plurality of rearwardly diver ing leaf springs, a base member sup orted by the outer end of each of said leaf springs, a pair of forwardly converging side walls substantially perpendicular to said base and havin outer edges adapted to cut through said foreign matter and a lura ity of soring teeth mounted on each of said base members and curved rearwardly and outwardly with their outer ends urged outwardly beyond said cutting edges to scrap foreign matter from the nine, said fingers bein disposed in stag ered relation, and said side walls limiting the distance said fingers can be bent toward the base.

12. In a pipe cleaning tool adapted to be moved through a pipe to scrape foreign matter from the inner surface thereof and having a plurality of rearwardly diverging leaf springs, a forwardly tapered base member supported by the outer end of each of said leaf springs, a pair of forwardly converging side walls substantially perpendicular to each of said base members, said sfdemaus .havifig outer edges Karam m through said foreign matter, spaced retaining .members' e221;en'ozl-ingecrosszeaehofisetid loasemem V bers 'meansrconneoting saidreta-iningr membersto 'wherebymreakagenf the :rods ism-avoided.

'P13. .'A p1OW adapted -to be moved :thnou'gh a. pipe shaving ram uneven'dnner surface .to scrape .toreign matter tram thatsnrface,.saielzplow eom prising a forward-1y; tapered sbase, 03, pair ot forwardly .xzonverging aside *walls substantially perpendicular tosaid base and having (outer edges adapted to-cut thwu'gh-said-foreign. matter and a plurality of spring fingers arranged rinalateb all-y s'extending rows rand-seemed ato said. base, said; fingers=being staggered with-rrespeet'to eaeh other and being ourvtedirom theebase reatwardlw and outwardly, the outer-wndsof the -fingers be -outwardly beyond isaid --"cutting *edges of the side walls to clean foreign matterfrom depressionsr not reached by said-edges said side Walls limiting the distance the fingers tat-n be bent, r-twhereby breakage of the .fingers Eis avoided.

V \fiAWRENCE :R. ROBINSON.

ROBINSON. EARL O. BERGER.

=WALTER :S.

REFERENCES EITEE r f 'rhe following references are-of 'record ih lth meer-ms patem q jUNITEDSTATES PATENT Germany we. fled-Jan. L12, 1924 

